I have a 2002 Saturn l100 died while driving has Gass an spark but will not start.

Pull the top cover for the timing belt. Put #1 cylinder on top dead center( compression stroke). Check the timing marks for the cam/s

Here's a link to the P0300 code and possible causes.Sounds like clogged fuel injectors. https://www.autocodes.com/p0300_saturn.html

It could be a bad coil assembly, or dirty fuel injectors. I would look at the coil box first.

check mass air flow sensor

For the original question, we had the same issue with a Saturn L100 - the fix was installing a new BCM - (Body Control Module).

sounds like a fuel pump check fuel pressure but it could b alot of things spark fuel compression timing check basics first

no,it sounds like the bcm,body control module is bad, take it to dealer

Remove spark plugs wires at coils.Have someone crank engine,should be spark jumping between coils whil cranking.If not most likely a crank postion sensor located on the rear of engine block.If not that other possibility is a ignition control module located under coils (flat plate w-one connector)Hope that helps

sounds like a wheel bearing sensor is giving trounble

checked your relay ?